I've never seen a post deleted in this form, enless it contained profane language, Or something similar. Are you sure you've just not missplaced it? I noticed two threads started by you in this forum.
Mysql is occasionaly slow, or perhaps your server is being boged down by someone else. Is other content on your site fast to load, or is it just phpbb? It may clear up on it's own in any other hour or two. If not, you can contact support and see if they can do anything.